Interface Routine<T>

Callable objects are mainly stored procedures and stored functions. The
distinction between those two object types is very subtle and not well
defined across various RDBMS. In general, this can be said:

Procedures:

Are called as callable statements

Have no return value

Support OUT parameters

Functions

Can be used in SQL statements

Have a return value

Don't support OUT parameters

But there are exceptions to these rules:

DB2, H2, and HSQLDB don't allow for JDBC escape syntax when calling
functions. Functions must be used in a SELECT statement